The convenience of wireless networking has led to a wide-scale adoption of wireless networks (e.g., IEEE 802.11 networks). Corporations, universities, homes, and public places are deploying these networks at a remarkable rate. However, a significant number of “pain points” remain for end-users and network administrators. Users experience a number of problems such as intermittent connectivity, poor performance, lack of coverage, and authentication failures. These problems occur due to a variety of reasons such as poor access point layout, device misconfiguration, hardware and software errors, the nature of the wireless medium (e.g., interference, propagation), and traffic congestion. Users frequently complain about connectivity and performance problems, and network administrators are expected to diagnose these problems while managing corporate security and coverage. Their task is particularly difficult due to the unreliable nature of the wireless medium and a lack of intelligent diagnostic tools for determining the cause of these problems.
For companies with a large deployment of IEEE 802.11 networks, there may be several thousand Access Points (APs) spread over many buildings. Problems with the networks result in end-user frustration and loss of productivity for the corporation. Furthermore, resolution of each end-user complaint results in additional support personnel costs to a company's IT department; this cost can be several tens of dollars and this does not include the cost due to the loss of end-user productivity.
Fault diagnostics in IEEE 802.11 infrastructure networks has not garnered attention from the research community relative to other higher profile areas of research in wireless networking. Several companies attempt to offer diagnostic tools, but these products lack a number of desirable features. For example, they do not do a comprehensive job of gathering and analyzing the data to establish the possible causes of a problem. Furthermore, most products typically only gather data from the APs and neglect the client-side view of the network. Some products that monitor the network from the client's perspective require hardware sensors, which can be expensive to deploy and maintain. Also, current solutions do not typically provide any support for disconnected clients, even though these are the ones that need the most help.